I'd favor Marquez but the fight(s) would be close and the decisions called into question ala Morales-Barerra and Pac-Marquez.
Morales is just the kind of fighter JMM thrives on, aggressive and brings the fight to him. He'll do just what Juan wants by taking the lead and JMM would counter him to death. I think just off of styles JMM beats him but the fact that I also think JMM was a better fighter helps too.
Morales on points. If Marquez chooses to counter punch, he won't win a decision. If he attempts to lead like he did against Juarez, he doesn't get the better of it.